Various exhaust braking devices have heretofore been provided for use on internal combustion engines embodying a turbocharger. Because of the design of such devices, they are possessed of one or more of the following shortcomings: (a) it is of bulky, complex construction and requires an inordinate amount of space when installed on an engine; (b) it is ineffective in controlling the maximum back pressure which is developed within the exhaust manifold and thus rendering the engine highly susceptible to damage; (c) when the device is in a back pressure developing mode, the turbine wheel of the turbocharger is idle thereby rendering various oil seals embodied in the turbocharger susceptible to leakage; (d) it causes slower acceleration of the turbine wheel when the device is moved from a braking mode to a non-braking mode; and (e) the device is highly susceptible to malfunction.